Piston for internal combustion engine



June 26, 1956 H. o. HEDGES 2,752,212

PISTON FOR INTERNAL COMBUSTION ENGINE Original Filed May 20, 1949 2 22 I22 v I 1 O 24 2O 2 l3 000000 2 v 90. j L g Y Z I S 5 l5 2 27 A N I "-P II j I 3 I I l. J I I 4 x: JO k 3/ J I INVENTOR Harry 0. Hedyes.

ATTORNEY PISTON FOR INTERNAL COMBUSTION ENGINE Divided and thisapplication July 3, 1952, Serial No. 297,024

1 Claim. (Cl. 309-8) This invention relates generally to internalcombustion engines and is more particularly concerned with improvedmeans for lubricating and sealing a piston cylinder, this applicationbeing a divisional of my original copending application filed May 20,1949, Serial No. 94,368, and now abandoned.

A principal object of the present invention is to provide in an engineof the aforementioned character a new and improved construction ofpiston having bafile means provided internally thereof in associationwith through passages in the cylindrical wall of the piston foreffecting positive delivery of oil outwardly of the piston upon eachupstroke of the latter to thereby efiectively lubricate and seal theupper reaches of the piston cylinder.

Other objects and advantages of the present invention will appear morefully hereinafter, it being understood that the present inventionconsists in the combination, construction, location and relativearrangement of parts, all as will appear more fully hereinafter, asshown in the accompanying drawings, and as finally pointed out in theappended claim.

In the accompanying drawings:

Figure 1 is a vertical sectional view of one form of internal combustionengine embodying the piston, construction of the present invention.

Figure 2 is a vertical sectional view of the piston per se; and

Figure 3 is an enlarged view of that portion of the piston embraced bythe broken line circle of Figure 2.

Referring now to the drawing and more particularly to Figure 1 thereofwherein is shown one preferred form of an engine constructed inaccordance with and embodying the principles of the present invention,it will be observed that the engine is provided with a water-jacketedcylinder suitably mounted upon the upper end of a crank case 11. Thecylinder 10 includes in suitable assembly a head 12, an upper body part13 and a lower body part 14, the aforementioned body parts beinglaterally extended to provide suitable supports and housing for theseveral valve mechanisms and fuel delivery passages.

The cylinder 10 is provided at its closed upper end with a suitablespark plug (not shown) and is fitted internally thereof with areciprocating piston 15 of an improved construction hereinafterspecifically described, the piston 15 being connected to the crank shaft16 of the engine through the intervention of a wrist pin 17 and aconnecting rod 13. The crank shaft and the connecting rod aresplash-lubricated by oil contained in the crank case 11, which oil iscarried upwardly by the piston and then forced outwardly thereof tolubricate the upper reaches of the internal walls of the pistoncylinder.

It will be observed that in the particular construction of engine asshown in the drawings hereof, the lower end of the piston is enlarged indiameter to snugly fit within an enlarged diameter lower section of thecylinder, the arrangement being such as to provide an auxiliary fuelpressure chamber 19 in which a charge of fuel may be compressed on eachup stroke of the piston and forced through atent O 2,752,212 PatentedJune'26, 1956 suitable communicating passages to the combustion chamberof a second cylinder associated with that shown, all as is moreparticularly shown and described in my copendingapplication Serial No.94,368 aforesaid.

In order to effectually seal the piston 15 within the lower end of thereduced section of its cylinder during reciprocation of the pistontherein, each said section of the cylinder is fitted in its lower endwith one or more suitable sealing ring sets 19 -49 to provide aneffective gaseous and fluid-tight seal between the piston and the bottomend of the reduced diameter portion of the cylinder.

Because of this last-mentioned gaseous and fluid-tight seal, passage oflubricating oil upwardly between the piston and the inner wall of thecylinder is effectually precluded, and, consequently, it becomesnecessary to provide some means for internally lubricating the wall ofthe reduced diameter section of the cylinder above the sealing ring sets19 -49 thereof.

Such means is shown particularly in Figures 2 and 3 wherein it will beobserved that the upper reach of the piston is internally providedadjacent its top end with an upwardly inclined battle element 20extending circumferentially about the full inner circumference of thehollow piston. This baffle forms conjointly with the inner wall of thepiston a V-shaped trough or channel 21 in which oil is accumulated bysplash action from the reservoir of oil in the crank case of the engine.The annular groove or channel 21 will receive a complement of oil oneach down stroke of the piston. Oil so accumulated in the annularreservoir 21 being subject to the force of inertia upon each up strokeof the piston, it is forced upon each such up stroke toward the bottomof its channeled reservoir. The piston wall is provided with a series ofcircumferentially spaced openings 22, the inner ends of whichcommunicate with the bottom of the channel 21, while their outer endsare in communication with an oil ring channel 23 in which is fitted oneof a series of conventional oil rings 24. The force of inertia actingupon the oil accumulated in the channel 21 during each up stroke of thepiston in its cylinder acts to force the oil outwardly of the channeledreservoir through the openings 22 to the oil ring immediately associatedtherewith and so provides controlled distribution of lubricating oil inthe normally inaccessible upper part of the cylinder. The oil is sodelivered to the external surface of the piston is returned upon eachdown stroke of the latter to the interior thereof preferably by way ofauxiliary oil passages 25 spaced circumferentially about the piston walland in communication with the lowermost piston ring groove 26. Theseauxiliary oil passages 25 may be dispensed with and in such case the oilmay be returned to the interior of the piston and thence to the crankcase by way of the oil ports 22 upon each down stroke of the piston.

If desired the piston 15 may be externally fitted with a removablesteel, or other suitable metal liner or jacket 27, the latter servingnot only to externally seal the bores 28-28 of the wrist pin bearingbosses 2929, but also to provide for increased life and wear of thepiston. It will be observed that the enlarged lower end of the piston isremovably secured to the lower end of the piston 15 by bolts 34}respectively projected through apertured lugs 31 formed in the enlargedlower end of the piston and threadedly engaging tapped bosses 32provided internally of the piston 15 as integral elements thereof.Consequently, the liner 27 is readily removable for replacement thereofand for any other service that may be required.

It will be understood, of course, that the construction of the presentinvention, as herein illustrated and described, is susceptible ofvarious changes and modifications which which may be made from time totime without departing from the general principles or real spirit of thepresent invention, and it is accordingly intended to claim the samebroadly, as well as specifically, as indicated in the appended claim.

What is claimed as new and useful is:

In an internal combustion engine 'of the character described, a pistonhaving baffle means formed internally thereof adapted upon each outward(nonpower) stroke thereof to force oil outwardly of the piston by way ofopenings formed in the side wall of the piston and in communication withan oil ring channel formed externally of the piston, the sidewall of thepiston being provided with additional openings in communication with asecond oil ring channel disposed below the first mentioned oil ringchannel and through which said oil may be forced inwardly of the pistonupon each inward (power) stroke thereof.

UNITED STATES PATENTS Hogan Oct. 19, 1915 Jones July 3, 1917 Jones July3, 1917 Riedler Mar. 12, 1918 Cook Nov. 4, 1924 Brower Apr. 10, 1928Best et a1. Mar. 3, 1931 Alexandrescu Mar. 20, 1934 Caldwell et a1 June15, 1937 Stadlman Feb. 22, 1949

